“In the early modern period,” begins Robert Eggers, writer and director of the deeply unsettling The Witch, “the real world and the fairy tale world were the same thing.” It’s an appropriately Once Upon a Time preamble for discussing the film, in which a devouter-than-thou family of New England Puritans venture past the outskirts of civilization, only to attract the attention of a primal—and terrifyingly implacable—force. “These days, the evil witch is more of a Halloween decoration,” Eggers says, “so we have to go back to the 17th century and be in that mindset to believe again. In that time, the idea of an evil witch was a given, like, a tree is a tree, a rock is a rock.”